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Force time trace select point to analyze from

Thank you Matt. The issue I have is that the baseline is not the same time with every effort analysed (the two I gave you earlier are 2 of 600). 

 

You are correct in saying I need a unique input for every case, yes. I need to get rid of the constant. 

 

I wouldnt be opposed to inputting the parameters, but what I was struggling with was being able to find the parameters and select those. As you can see from those two examples I gave you, the value of the baseline can change. I could figure out how to input parameters such as the value of the baseline and work around the millisecond thing as well, that would save a bunch of time.

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To address the issue of finding the parameters, the baseline is the average prior to the deviation correct? Could you not take an average of a time when you know the deviation is not occurring and then the output of that average be the baseline? In terms of establishing when the deviation occurs could you do this by looking at a graph of your data and selecting datapoints where it looks like the deviation has not occured and average that range of data points to obtain the baseline?

 

You mentioned 600 different inputs. Is that 600 number the possibilities that the baseline could be or is there some sort of sequence where you test your data against 600 different baselines? I think where we are having difficulties is I am still not 100% sure on what this baseline is? Is this baseline going to be specific to each individual time this test is run? If so why are there 600 different inputs?

Matt P.
Applications Engineer
National Instruments
Message 12 of 20
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That sounds good. But how do I select the datapoints in Labview? That was the main question I had. Is it possible to select datapoints to analyse from?

 

The baseline is different with each test (24 tests per person, 28 people = 672 to analyse). The baseline should be a straight line prior to the onset of contraction. The value of this is not always zero. It can fluctuate dependant on the persons limb weight or stiffness etc. Therefore definining the baseline needs to be a bit more variable. But this could not be an issue if I knew how to select datapoints to analyse from in labview. Thanks again for the help so far

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Message 13 of 20
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Because your data is in the form of a 1D array you can use the array subset VI to retrieve a small subset from your array of data. You can then take an average of all the points in the subarray and that will then be your baseline.

Matt P.
Applications Engineer
National Instruments
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Message 14 of 20
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How would I select/determine the small subset because it could be different for everyone?

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I have added a small edit to your code. I cannot run your code here in the office because of missing VI's. What I have added will need to be edited to fit your application. I added a while loop that allows the user to see the data. Visually determine where the flat baseline occurs and can enter the parameters to get the sub array. The user then click the calculate baseline button and the while loop will output the new baseline from the mean and out put the full array of data. This occurs immediately before the RTD VI. 

Matt P.
Applications Engineer
National Instruments
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Hi Matt,

Thank you again. However I have just attempted to open your VI and its must've been made in a different Labview version to mine. I have Labview 2013.
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Message 17 of 20
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Hi Matt,

 

I was just wondering if you had any luck with writing this in Labview 2013? Otherwise, does anyone know how I can open VIs that were created in a later version of Labview?

 

Regards,

Ryan

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Message 18 of 20
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Ryan,

 

I have been out of office these past few weeks. I was able to save the VI  for 2013. Here is the VI. My apologies for the delay. 

 

Matt P.
Applications Engineer
National Instruments
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Message 19 of 20
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Dont apologise Matt. I appreciate all the help. I will let you know how i go

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